The present invention is directed to a multimedia backwashable filter system and, more particularly, to a multimedia water treatment unit and rotatable control valve therefor.
Multimedia fluid treatment systems have been employed in the past for the treatment of various fluids, such as water. In these systems, various different treatment media have been employed in serial relationship to each other so that for example one medium may have a beneficial effect on subsequent downstream media. For example, in Heskett U.S. Pat. No. 5,415,770 it is disclosed that the use of certain finely divided metals, such as alloys of copper and zinc, may be employed as an upstream treatment medium to remove certain chemical constituents, such as residual chlorine, prior to subjecting water to other downstream water treatment media, such as activated carbon and/or an ion exchange medium. By removing the chlorine, the function and life of the latter two media may be improved and extended.
In such prior systems the several respective media are frequently located in several distinct units which are physically separated from each other and the fluids are passed through these distinct units in a serial fashion. These individual units can be individually serviced but they are demanding of space and material. Where the several respective media are contained in a single container or tank, they are difficult to maintain separate from each other, particularly due to the wide disparity in weights and/or sizes of media particles. Even where they can be maintained separate from each other, the placement of each of the media in the same tank makes it physically difficult to service or replace one medium without replacing the others due to their positioning relative to each other. Another disadvantage, particularly in small countertop water treatment units, is that no provision is currently known to permit rinsing or backwashing of the media which, if possible, might greatly extend the life of the system and their respective media.
It is the purpose of the present invention to avoid and eliminate the aforementioned disadvantages. In the present invention, a multimedia fluid treatment unit with an efficient rotatable control valve is provided which is compact, permits ready servicing of the unit and the utilization of a number of different media in the unit, and which prolongs the life of the unit by selective arrangement of the several media relative to each other to remove compounds which might be harmful to some of the media and by permitting rinsing and backwashing of the several media. Moreover, in the present invention a plurality of media containing containers are provided which are removably fixed to each other to facilitate replacement and service.
In one principal aspect of the present invention, a multimedia fluid treatment unit comprises a plurality of discrete containers stacked upon each other. Each of the discrete containers has an inlet for fluid at one location thereon and a discharge for fluid opposite the inlet. Each container is positioned in series flow relationship to the next adjacent container, and each of the containers defines a chamber for receiving and retaining a finely divided fluid treatment medium therein and between the fluid inlet and discharge whereby the fluid to be treated will flow through the medium in each chamber and serially to the medium in the next chamber. A valve is associated with the containers and is operable to a first service position in which the fluid to be treated is introduced to the containers and the fluid which is treated by the media in the containers is removed from the containers and discharged, to a second rinse position in which the treatment medium in the chambers is rinsed, and to a third backwash position in which the treatment medium in the chambers is backwashed.
In another principal aspect of the present invention, each of the containers includes a floor which includes perforations therein to form the discharge and contain the medium in the chamber of the container.
In still another principal aspect of the present invention, a mesh material is supported on the floor to contain the medium in the chamber of the container.
In still another principal aspect of the present invention, each of the containers is removably attached to its next adjacent container.
In still another principal aspect of the present invention, the fluid treatment medium is a water treatment medium which may be two or more of finely divided metals or alloys thereof, activated carbon, inert particulates and/or ion exchange media.
In still another principal aspect of the present invention, a housing has an elongate cylindrical chamber therein, and first, second, third and fourth passages extending through the housing and communicating with the cylindrical chamber. A valve includes a cylindrical valve body mounted for rotation in the cylindrical chamber, and the valve body has an axially extending passage therein which communicates with a source of fluid supply for the valve. The valve body has a first area adjacent its cylindrical surface which is aligned with the first and fourth passages, and a second area also adjacent its cylindrical surface which is aligned with the second and third passages. The valve body also includes first and second ports communicating between the axially extending passage and the first area, and a third port communicating between the axially extending passage and the second area. The cylindrical valve body is selectively rotatable between the first service position in which the first port communicates with the first passage and the second passage communicates with the third passage, the second rinse position in which the second port communicates with the first passage, and the third backwash position in which the third port communicates with the second passage and the first passage communicates with the fourth passage.
In still another principal aspect of the present invention, the aforementiored housing includes fifth and sixth passages extending through the housing and communicating with the cylindrical chamber, and the cylindrical valve body has a third area adjacent its surface which is aligned with the fifth and sixth passages, and fourth and fifth ports communicating between the axially extending passage and the third area. The fifth passage communicates with the fourth port when the cylindrical valve body has been rotated to the second rinse position, and the sixth passage communicates with the fifth port when the cylindrical valve body has been rotated to the third backwash position.
In still another principal aspect of the present invention, the aforementioned housing includes a seventh passage extending through the housing and communicating with the first area, and the first area is aligned with the seventh passage so that the seventh passage communicates with the fourth passage when the cylindrical valve body has been rotated to the second rinse position.
In still another principal aspect of the present invention, the multimedia fluid treatment unit includes sediment retaining means adjacent the discharge of the most downstream container when the valve is in the first service position for retaining fine particles which may have passed through the chambers of the containers during the treatment of the fluid. The aforementioned seventh passage communicates with the fourth passage to discharge such fine particles from the sediment retaining means when the valve is positioned in the second rinse position.
In still another principal aspect of the present invention, the multimedia fluid treatment unit includes at least one fluid treatment medium which is an ion exchange medium and a container for the production and containment of a fluid composition for the regeneration of the ion exchange medium. The fifth and sixth passages communicate with the last mentioned container to introduce fluid to and discharge fluid from the container.
In still another principal aspect of the present invention, the aforementioned seventh passage defines an overflow for the container for the composition and communicates with the first area, the first area is aligned with the seventh passage, and the seventh passage communicates with the fourth passage when the cylindrical valve body has been rotated to the second rinse position.
In still another principal aspect of the present invention, the aforementioned second passage is sealed when the cylindrical valve body is rotated to the second rinse position, the fifth and sixth passages are sealed when the cylindrical valve body is rotated to the first service position, the sixth passage is sealed when the cylindrical valve body is rotated to the second rinse position, the fifth passage is sealed when the cylindrical valve body is rotated to the third backwash position, and the aforementioned seventh passage is sealed when the cylinder is rotated to the first and third positions.
In still another principal aspect of the present invention, the aforementioned sealing is by a seal on the surface of the valve body in the second area which aligns with the second passage when the valve body is rotated, by seals on the surface of the valve body in the third area which align with the fifth and sixth passages when the valve body is rotated, and by a seal on the surface of the valve body in the first area which aligns with the seventh passage when the valve body is rotated.
In still another principal aspect of the present invention, the surface of the cylindrical valve body in the first and second areas is spaced from the surface of the chamber in the housing to define an annular passage between the surfaces, and the first, second and third areas are divided from each other to define first and second annular passages at the first and second areas respectively.
In still another principal aspect of the present invention, the first, second and third areas are divided from each other by O-rings about the cylindrical valve body to define the first and second annular passages.
In still another principal aspect of the present invention, the cylindrical valve body comprises a single cylinder.
These and other objects, features and advantages of the present invention will be more clearly understood through a consideration of the following detailed description.